The conventional industrial blast furnace process of iron production from its oxides (Fe2O3 or Fe3O4) involves carbothermic reduction to produce molten pig iron and slag consisting of oxides like FeO, SiO2, Al2O3, CaO, MgO, etc. The main chemical reaction that gives rise to molten iron can be described asFe2O3+3CO→2Fe+3CO2 
Preheated blast air blown into the furnace reacts with the carbon in the form of coke to produce carbon monoxide and heat. The carbon monoxide then reacts with the iron oxide to produce molten iron and carbon dioxide. Hot carbon dioxide, unreacted carbon monoxide, and nitrogen from the air pass up through the furnace as fresh feed material travels down into the reaction zone.
There are several environmental issues linked to blast furnace operation:                1. About 1.9 ton of CO2 is produced per ton of crude steel.        2. Approximately 5% CO2 in the atmosphere is due to steel industry.        3. Other gases such as SOx and NOx are produced during coke making and blast furnace operation.        4. Solid waste such as slag has to be treated and disposed economically.        
The following table shows the theoretical production of CO and CO2 in iron making for carbothermic reduction of hematite vis-a-vis production of water vapor in hydrogen reduction of hematite after considering the following reactions.Fe2O3+3C→2Fe+3CO  (i)Fe2O3+1.5C→2Fe+1.5CO2  (ii)Fe2O3+H2→2Fe+3H2O  (iii)
TABLE 1Shows requirements of different reductants and their gaseous productfor the production of one ton of metal.(in Ton)ReactionIronCH2COCO2H2O(i)1123684(ii)1121866(ii)112654
The CO and CO2 generation in commercial blast furnaces are higher than above figures. In addition to this, there are further generations of these gases in the coke oven plant while preparing coke for blast furnace. In contrast, it is quite clear that reduction by hydrogen only produces water which is environmentally benign. The process may be described as chimneyless process since there is no CO or CO2 emission. The unreacted hydrogen in case of plasma process can be recycled after condensation and removal of water vapor.
Solid state direct reduction of iron ore using carbon in the form of non coking coal at temperatures below the melting point of iron, produces sponge iron or directly reduced iron (DRI), which is a spongy mass consisting of a mix of incandescent wrought iron and slag. The conventional DRI process is not environment friendly. It produces higher quantity of CO and CO2 and the product normally consists of very high carbon content which is not desirable in the competitive market. The reducing gas is obtained by catalytic methane reforming in which coking and carbon formation on the catalyst and deactivations are the main disadvantage. It would be advantageous if a different process is conceived where methane gas and catalysts are completely eliminated.
The new technology proposed herein involves solid state extraction of carbon free iron from iron ore, using low temperature hydrogen plasma. Hydrogen plasma serves both as the heating source as well as the reductant. Hydrogen reduction of iron oxide being highly endothermic, plasma stage reduction is ideally suited compared to gas stage reduction. The chemical driving force, ΔG0, for hydrogen atom as well as hydrogen ion (constituents of hydrogen plasma) with iron oxide is reported to be up to 3 and 15 times, respectively, lower than that involving molecular hydrogen and iron oxide. Thus the kinetics of reduction is expected to be faster by an order of magnitude in hydrogen plasma. For example, the rate of oxygen removal in smelting reduction of iron oxide by carbon at 1600° C. is 0.064 g/cm2·min where as it is about 0.53 g/cm2·min for hydrogen plasma smelting reduction.
The present invention opens up exciting possibilities as outlined below.                1) The size of the reactor/furnace shall be drastically reduced for a given throughput in case of continuous reactor.        2) Unlike conventional iron extraction process that includes multiple stages such as coke oven plant, pelletization/sintering, the plasma smelting would involve only one stage process.        3) Electric power consumption for plasma metallurgical furnaces can be high but as compared to conventional blast furnace the total energy consumption per ton of hot metal (HM) would be less in case of thermal plasma system. For example, the total energy consumption for iron oxide reduction works out to be 12.06 GJ/ton HM in case of hydrogen reduction process; where as it is 14.07 GJ/ton HM in blast furnace process. If energy spent in pelletization and sintering of ore fines and coke making are included, the total energy for molten metal making in BF process goes up to 19.49 GJ/ton HM but in the hydrogen reduction process it does not increase from 12.06 GJ/ton HM as preprocessing of ore is eliminated.        4) It eliminates the energy-intensive coke-making process. Flux mixing shall be very minimal to reduce impurities like P, S, Al, Si, etc. in the liquid metal by slag separation.        5) Since there is no involvement of coke, the product would be free from C and S which will improve product quality. Concentration of impurities like C, S, & Si, would be lower in comparison to the iron produced through conventional route.        6) In plasma condition, ore fines can be charged into the reactor.        7) The absence of effluents like CO/CO2 would attract carbon credit.        